Punching apparatus

ABSTRACT

A punching apparatus for punching shapes out of sheet material by means of punching tools. A punching table made of bendable material is pressed toward the punching tools by a presser cylinder as the cylinder is moved in contact with and along one surface of the bendable punching tables while pressure is exerted against the opposite punching table surface by counter pressure means through said tools and through said sheet material to be punched.

United States yatent Spengler 1 PUNCHING APPARATUS [75] Inventor:' Ernst Maximilian Spengler,

Huesenstamm near ()ffenbach am Main, Germany [73] Assignee: Stanzlechnik GmbH Roeder &

Spengler, Bergen-Enkheim, Germany 221 Filed: Apr. 10, 1972 21 1 Appl. No.: 242,740

Related US. Application Data [62] Division of Ser. No. 32,294, April 27, 1970, Pat, No.

[30] Foreign Application Priority Data May 7, 1969 Germany.....' 6918475[U] Apr. 4, 1970 Germany 2016182 [52] U.S. Cl 83/401, 83/510, 83/542, 83/566 [51] Int. Cl 826i 1/00 [58] Field of Search 83/542, 510, 512, 566-569, 83/401 June 4, 1974 [56] References Cited UN [TED STATES PATENTS l75,069 3/1876 Giraudat 83/512 2,405,868 8/1946 Whittaker et al..... 83/566 2,688,367 9/1954 Maeser 83/512 3,528,335 9/1970 Andolsek 83/510 X FOREIGN PATENTS OR APPLICATIONS 1,044,583 11/1958 Germany 83/510 Primary Examiner.l. M. Meister Attorney, Agent, or Firm-W. G. Fasse [5 7] ABSTRACT A punching apparatus for punching shapes out of sheet material by means of punching tools. A punching table made of bendable material is pressed toward the punching tools by a presser cylinder as the cylinder is moved in contact with and along one surface of the bendable punching tables while pressure is exerted against the opposite punching table surface by counterpressure means through said tools and through said sheet material to be punched.

14 Claims, 7 Drawing Figures PATENTEUJUH mm 38113378 sum 2 0F 1 I FATENIEUJUH 419M $813378 Fig. 3

PATENTEDJUH 41914 SHEET '3 OF 7 Fig. 7

PuNcniNo APPARATUS This application is a divisional application of my copending application Ser. No. 32,294 filed Apr. 27, 1970, now US. Pat. No. 3,703,l 18; issued on Nov. 21,

The present invention relates to a punchingapparatus for stamping or punching workpieces from sheet material, for example, for cutting pieces of cloth of predetermined size and shape, so called patterns, from webs of cloth for the production of ready-made clothmg.

Stamping or punching devices suitable for the above and other purposes are known in the art and different embodiments or constructions are available.

One construction which is known as a rotary punching apparatus employes a stationary punching table on which the material to be punched, cut or stamped is lo.- cated while the punching tools or dies are arranged on the circumference of a cylindrical roller. The workpieces are punched out by rolling the die carrying roller relative to and on the punching table.

A drawback of this known construction is seen in that the sheet material or webbing to be punched out is subjected to distortion due to the substantial pressure which is supplied to the punching roller whereby such distortions result in warping and buckling. As a result the punched patterns frequently do not meet the size and shape requirements.

Another disadvantage of the punching apparatus employing a rotary punching cylinder or roller is seen in that the material to be punched, and especially soft material, forms a so called bow-wave which is pushed ahead of the punching roller whereby the material is also distorted due to such bow-wave. In this instance as well as in the first mentioned instance the punched out pattern will not have the desired size and shape.

The above considerations also apply to known constructions or punching devices which are referred to as roller punches in which the punching dies or tools are supported in a plane and the stamped out pattern is formed by two presser rollers. The stamping tools or dies as well as the material to be punched are moved through a gap between the two presser rollers as part of the punching operation.

A third group of known punching devices comprises so called bridge punches and swivel amt punches. These devices have the advantage that material distortions, due to the formation of said bow-waves, is avoided. However, the drawback of this group is seen in that a very high punching pressure is required.

' OBJECTS OF THE INVENTION In view of the foregoing it is an object of the invention to remove the outlined drawbacks.

More specifically, it is an object of the invention to avoid distortions of the material to be punched so that the material will neither be buckled nor warped and the punched out workpieces will retain their size and shape.

It is yet another object of the invention to avoid unusually high stamping or punching pressures.

Yet another'important object of the' invention is to completely depart from the prior art by avoiding a direct contact between either a tool carrying punching roller and the material to be punched or between a presser roller and the material to be punched.

A still further object of the invention is to provide a bendable or flexible punching table between the material to be punched and a presser cylinder whereby-the pressure is supplied indirectly to the material.

Another object of the invention is to provide conveyor means which advance the material to be punched on to a bendable or flexible punching table, preferably in a direction which extends across the direction of movement of a presser cylinder.

SUMMARY OF THE INVENTION The above objects have been achieved according to the invention in that the punching table of the present punching apparatus is made of a flexible or bendable material which carries the material to be punched and preferably also the punching tools or dies which, in the simplest version, are placed on top of the material to be punched. In another version the punching tools are supported above the material-by counter presser means arranged above the punching table. A presser cylinder is arranged underneath the punching table. The presser cylinder is movable perpendicularly to its longitudinal axis, for example, on guide means such as rails supported in a machine frame in such a manner that a presser roller can move along the entire extent of the punching table.

In order that the invention may be clearly understood, it will now be described, by way of example, with reference to the accompanying drawings, wherein: I

FIG. 1 shows a front view of a further embodiment of the apparatus according to the present invention;

FIG. 2 shows a top view of the apparatus as illustrated in FIG. 1 whereby the counter presser means have been omitted;

FIG. 3 illustrates a side view of the apparatus illustrated in FIGS. 1 and 2;

FIG. 4 shows a detail portion of FIG. 1 on an enlarged scale;

FIG. 5 is a side view similarto that of FIG. 3, however, with modified conveyor means for the material to be punched;

FIG. 6 shows a side view similar to that of FIG. 5 of a modified embodiment of an apparatus according to the invention; and

FIG. 7 is a top view of the apparatus according to FIG. 6.

DESCRIPTION OF EXAMPLE EMBODIMENTS frame 30 by means of threaded spindles 32. Drive means (not shown) for the spindles 32 permit the raising and lowering of the counter presser means 31, 33.

However, the use of a threaded spindle for the support of the counter presser means 31, 33 is not absolutely necessary and any other manner of supporting the counter presser means is in keeping with the present teachings.

Referring specifically to FIG. 4, the tools or knives 34 are attached to the tool carrying frame 33 by means of U-shaped channels.

The punching table comprises a relatively thin sheet 35 of steel which is clamped in a table frame 36 in such a manner that the sheet 35 is under tension within the area defined by the table frame 36. The sheet 35 may have such a size that portions of it protrude out of the table frame 36 in the directions in which the presser cylinder 4} is moving so that the protruding ends may rest on the presser cylinder 4 when the latter is in one or the other of its extreme positions outside of the area defined by the table frame 36. The clamping of the sheet 35 in the table frame 36 is done in such a manner that the steel of the sheet 35 is stretched substantially to its elastic limit; The sheet 35 is then rigidly clamped to the frame 36 by clamping bars 36 secured to the frame 36. In this manner it is assured that the above mentioned bow-wave ahead of the moving presser cylinder 4 is avoided.

Drive means 37 are provided for raising and lowering the sheet 35 along with its table frame 36 as indicated by the vertical double arrows in FIG. 4. The power source for the drive means 37 may be, for example, hydraulic or pneumatic or electric.

Underneath the tool carrying frame 33 and facing the sheet 35 there are attached, for example, by screws, spacer rods 38 which limit the spacing between the cutting edges of the punching knives 34 and the sheet 35.

Between the sheet 35 of steel and the punching knives 34 there is arranged, preferably in a direction extending perpendicularly to the direction of movement of the presser cylinder 4 a carrier 39 for the material 19 to be punched. Preferably, the carrier 39 is movable intermittently. Moving means for this purpose are well known. It is not necessary that the carrier 39 moves across the direction of movement of the presser cylinder 4. The carrier 39 may also move in the direction or counter to the direction of presser cylinder 4.

In the embodiment of FIGS. I to d the carrier 39 is comprised of an endless conveyor belt 40 which is resiliently supported in the machine frame, for example, by rollers subject to spring forces. However, the support of-the conveyor belt 40 is not critical and thus FIGS. 1 and 3 merely illustrate the support means for the conveyor belt 40 in a schematic manner. For example, the conveyor belt 40 may run over upper direction reversing rollers 41, 42 and over lower guide roller 43, 44 supported by conventional means in the machine frame 30. The rollers 41 to 44 may be supported by suitable posts 45, 46 including supporting arms 67, 48 for the direction reversal rollers 41, 42.

The material 19 to be punched is placed on the conveyor belt 40 preferably on top of suitable plates 49 which are moved intermittently into the punching apparatus and intermittently out of the punching apparatus.

Instead of using a conveyor belt or band 40 the carrier 39 for the material 19 to be punched could comprise a plurality of plates operatively associated with conveyor means in form of endless chains. This'arrangement would correspond to that of FIG. 3 whereby the conveyor belt 410 would merely be replaced by respective chain drives and the rollers 41 to 44 would be replaced by respective chain drive wheels.

Referring to FIG. 5 there is shown a modified version of the present apparatus. The center portion of the apparatus of FIG. 5 is quite similar to that of FIG. 3. However, instead of raising and lowering the table frame 36 by means of a single drive member 37, FIG. 5 illustrates two such drive members 37, one arranged on each side of the center portion of the apparatus. Moreover, the carrier member 39 of FIG. 3 has been replaced by platesfor which there is arranged an infeed table 50 at the input side of the apparatus and an output receiving table 51 at the output side of the apparatus. Both, the infeed table 50 as well as the output receiving table 51 comprise a movable top surface, for example, in the form of rollers 52, 53. Such rollers arranged in the form of runways are well known in the art. The plates themselves are not shown in FIG. 5 for simplicitys sake.

The embodiment of FIG. 6 is similar to that of FIG. 5. However, the infeed table and the output receiving table 61 are modified by means 62, 63 for raising and lowering the punching tools or knives 34. These raising and lowering means comprise holding members, for example, in the form of bars 62a, 63a which are adapted for holding the punching knives 34 by electromagnetic forces and which in turn are raised and lowered by respective piston cylinder arrangements 62b, 63b, resting on horizontal cross bars 620, 63c.

In the embodiment of FIG. 7 the infeed table 60 and the output receiving table 61 are provided with guide beds 60a, 61a which extend sidewise. The tool raising and lowering means 62, 63 which comprise said horizontal cross bars 620, 63c which ride on or in said guide beds 60a, 61a on glide blocks 62d, 63d whereby the tool raising and lowering means maybe shifted, for example, by hand back and forth as indicated by the two double arrows in FIG. 7. Details of such raising and lowering electromagnetically operated tool support means are described and shown, for example, in the present applicants US. application Ser. No. 883,856, filed on Dec. 10, 1969, now abandoned, continuation application filed Aug. 13, 1971, Ser. No. 171,520 now allowed.

The present invention is not limited to the embodiments shown and described. Modifications may be made by those skilled in the art without deviating from the present teachings. For example, rather than placing the material to be punched on top of the present punching table and the counter presser means on top of the material with the tools arranged between the material and the counter presser means above the punching table and placing the presser cylinder below the punching table, it would be possible to reverse the arrangement whereby the presser cylinder would be located above the punching table while the tools and the material would be supported by the counter presser means below the punching table. Accordingly, it is intended to cover all modifications and equivalents within the scope of the appended claims.

What I claim is:

l. A punching apparatus comprising a machine frame, a punching table made of bendable sheet material and having two surfaces, means for supporting the punching table in said machine frame, means for locating punching tools on one side of said punching table adjacent to one of said two surfaces for cooperating with said punching table to punch shapes out of flat material located between the tools and said one table surface, counter pressure means also located on said one side of the punching table with said punching tools arranged between the counter pressure means and said material to be punched, means for supporting the counter pressure means for cooperation with the punching tools, a presser cylinder having a longitudinal axis, guide means supported in said machine frame for movably supporting said presser cylinder on the other side of the punching table, and drive means operatively connected to the presser cylinder for moving the presser cylinder along said guide means in contact with the other of said two surfaces of the bendable punching table and in a direction extending perpendicularly to said longitudinal cylinder axis and in parallel to said punching table, said apparatus further comprising carrier means for said flat material to be stamped, said carrier means being located between said punching tools and said sheet of bendable material, and means operatively associated with said carrier means for moving the carrier means across the punching table in a direction extending perpendicularly to the direction of movement of the presser cylinder.

2. The punching apparatus according to claim 1, wherein said carrier means for the material to be punched comprises a plurality of supporting plates and conveyor means operatively associated with said supporting plates for advancing the plates through the apparatus.

3. The punching apparatus according to claim 1, wherein said supporting means for the counter pressure means comprise means for movably connecting the counter pressure means to said machine frame, said apparatus further comprising lifting means operatively associated with said counter pressure means for lifting the counter pressure means off the punching table, said counter pressure meansfurther comprising a limiting bar attached to said connecting means so that the limiting bar faces the punching table, said limiting bar having a given thickness to take up a corresponding space between the connecting means and the punching table whereby the spacing between cutting edges of said punching tools and the punching table is limited.

4. The punching apparatus according to claim ll, wherein said means for supporting the punching table comprises a table frame and means for rigidly clamping the sheet material of the punching table in'a stretched condition to said table frame, said guide means for the presser cylinder being longer than the length of said table frame in the direction of presser cylinder movement so that the presser cylinder is movable into positions ahead and beyond said table frame, and wherein said sheet of bendable material has an area larger than that defined by the table frame so that portions of the sheet material of the punching table protrude outside the table frame in said direction of presser cylinder movement whereby said protruding portions of the sheet rest on said presser cylinder when it is in its extreme positions outside the area defined by the table frame.

5. The punching apparatus according to claim l,

wherein said counter pressure means comprise a pair of 0 parallel bars, means for supporting the parallel bars on said frame structure, connecting means for interconnecting the parallel bars with each other, said connecting means fonning tool carrier means to which said tools are removably attached.

6. The punching apparatus according to claim 1, further comprising drive means operatively connected to said means for supporting said punching table for raising and lowering said punching table in said machine frame.

7. The punching apparatus according to claim 3, further comprising means for raising and lowering the counter pressure means.

8. A punching apparatus comprising a machine frame, a punching table made of bendable sheet mate rial and having two surfaces, means for supporting the punching table in said machine frame, means for locating punching tools on one side of said punching table adjacent to one of said two surfaces for cooperating with said punching table to punch shapes out of flat material located between the tools and said one table surface, counter pressure means also located on said one side of the punching table with said punching tools arranged between the counter pressure means and said material to be punched, means for supporting the counter pressure means for cooperation with the punching tools, a presser cylinder having a longitudinal axis, guide means supported in said machine frame for movably supporting said pressure cylinder on the other side of the punching table, and drive means operatively connected to the presser cylinder for moving the presser cylinder along said guide means in contact with the other of said two surfaces of the bendable punching table and in a direction extending perpendicularly to said longitudinal cylinder axis and in parallel to said punching table, and wherein said means for supporting the punching table in said machine frame comprise a table frame located in said machine frame, and means for clamping the sheet material of the punching table to said table frame to rigidly hold the sheet material of the punching table in a stretched condition.

9. The punching apparatus according to claim 8, further comprising drive means connected to said table frame for raising and lowering the table frame in the machine frame.

10. The punching apparatus according to claim 8, further comprising means connected to said counter pressure means for raising and lowering the counter pressure means.

11. The punching apparatus according to claim 8, wherein said presser cylinder is movable from an end position outside one end of said table frame to another end position outside the opposite end of said table frame.

12. The punching apparatus according to claim 8, wherein said sheet material of the punching table has a length longer than said table frame so that the ends of said sheet material of the punching table protrude from said table frame to rest on said presser cylinder when the latter is in its end positions.

13. The punching apparatus according to claim 8, further comprising an infeed table and an output receiving table, each having a movable table surface, a supporting structure above said movable table surface, said supporting structure including means for holding, raising, and lowering said punching tools.

14. The punching apparatus according to claim 13, wherein said infeed and output receiving tables each comprise guide bed means for said supporting structure, means connected to said supporting structure and movable along said guide bed means for laterally moving the supporting structure along the guide bed means across the direction of movement of the carrier means. 

1. A punching apparatus comprising a machine frame, a punching table made of bendable sheet material and having two surfaces, means for supporting the punching table in said machine frame, means for locating punching tools on one side of said punching table adjacent to one of said two surfaces for cooperating with said punching table to punch shapes out of flat material located between the tools and said one table surface, counter pressure means also located on said one side of the punching table with said punching tools arranged between the counter pressure means and said material to be punched, means for supporting the counter pressure means for cooperation with the punching tools, a presser cylinder having a longitudinal axis, guide means supported in said machine frame for movably supporting said presser cylinder on the other side of the punching table, and drive means operatively connected to the presser cylinder for moving the presser cylinder along said guide means in contact with the other of said two surfaces of the bendable punching table and in a direction extending perpendicularly to said longitudinal cylinder axis and in parallel to said punching table, said apparatus further comprising carrier means for said flat material to be stamped, said carrier means being located between said punching tools and said sheet of bendable material, and means operatively associated with said carrier means for moving the carrier means across the punching table in a direction extending perpendicularly to the direction of movement of the presser cylinder.
 2. The punching apparatus according to claim 1, wherein said carrier means for the material to be punched comprises a plurality of supporting plates and conveyor means operatively associated with said supporting plates for advancing the plates through the apparatus.
 3. The punching apparatus according to claim 1, wherein said supporting means for the counter pressure means comprise means for movably connecting the counter pressure means to said machine frame, said apparatus further comprising lifting means operatively associated with said coUnter pressure means for lifting the counter pressure means off the punching table, said counter pressure means further comprising a limiting bar attached to said connecting means so that the limiting bar faces the punching table, said limiting bar having a given thickness to take up a corresponding space between the connecting means and the punching table whereby the spacing between cutting edges of said punching tools and the punching table is limited.
 4. The punching apparatus according to claim 1, wherein said means for supporting the punching table comprises a table frame and means for rigidly clamping the sheet material of the punching table in a stretched condition to said table frame, said guide means for the presser cylinder being longer than the length of said table frame in the direction of presser cylinder movement so that the presser cylinder is movable into positions ahead and beyond said table frame, and wherein said sheet of bendable material has an area larger than that defined by the table frame so that portions of the sheet material of the punching table protrude outside the table frame in said direction of presser cylinder movement whereby said protruding portions of the sheet rest on said presser cylinder when it is in its extreme positions outside the area defined by the table frame.
 5. The punching apparatus according to claim 1, wherein said counter pressure means comprise a pair of parallel bars, means for supporting the parallel bars on said frame structure, connecting means for interconnecting the parallel bars with each other, said connecting means forming tool carrier means to which said tools are removably attached.
 6. The punching apparatus according to claim 1, further comprising drive means operatively connected to said means for supporting said punching table for raising and lowering said punching table in said machine frame.
 7. The punching apparatus according to claim 1, further comprising means for raising and lowering the counter pressure means.
 8. A punching apparatus comprising a machine frame, a punching table made of bendable sheet material and having two surfaces, means for supporting the punching table in said machine frame, means for locating punching tools on one side of said punching table adjacent to one of said two surfaces for cooperating with said punching table to punch shapes out of flat material located between the tools and said one table surface, counter pressure means also located on said one side of the punching table with said punching tools arranged between the counter pressure means and said material to be punched, means for supporting the counter pressure means for cooperation with the punching tools, a presser cylinder having a longitudinal axis, guide means supported in said machine frame for movably supporting said pressure cylinder on the other side of the punching table, and drive means operatively connected to the presser cylinder for moving the presser cylinder along said guide means in contact with the other of said two surfaces of the bendable punching table and in a direction extending perpendicularly to said longitudinal cylinder axis and in parallel to said punching table, and wherein said means for supporting the punching table in said machine frame comprise a table frame located in said machine frame, and means for clamping the sheet material of the punching table to said table frame to rigidly hold the sheet material of the punching table in a stretched condition.
 9. The punching apparatus according to claim 8, further comprising drive means connected to said table frame for raising and lowering the table frame in the machine frame.
 10. The punching apparatus according to claim 8, further comprising means connected to said counter pressure means for raising and lowering the counter pressure means.
 11. The punching apparatus according to claim 8, wherein said presser cylinder is movable from an end position outside one end of said table frame to another end position outside thE opposite end of said table frame.
 12. The punching apparatus according to claim 8, wherein said sheet material of the punching table has a length longer than said table frame so that the ends of said sheet material of the punching table protrude from said table frame to rest on said presser cylinder when the latter is in its end positions.
 13. The punching apparatus according to claim 8, further comprising an infeed table and an output receiving table, each having a movable table surface, a supporting structure above said movable table surface, said supporting structure including means for holding, raising, and lowering said punching tools.
 14. The punching apparatus according to claim 13, wherein said infeed and output receiving tables each comprise guide bed means for said supporting structure, means connected to said supporting structure and movable along said guide bed means for laterally moving the supporting structure along the guide bed means across the direction of movement of the carrier means. 